This compartment is a site for stenosing tenosynovitis (de Quervain tenosynovitis), characterized by inflammation of the synovial lining of the tunnel that narrows the opening and results in pain when the tendons move.

Compartment II:

On the radial side of the radial tubercle, it houses the extensor carpi radialis longus and brevis.

Compartment III:

On the ulnar side of the radial tubercle, it contains the extensor pollicis longus.

This compartment defines the ulnar border of the snuffbox.

Palpates along the length of this tendon to feel for signs of rupture.

It is not uncommon to find this tendon ruptured in association with rheumatoid arthritis.

Compartment IV:

Lies just ulnar to compartment III and just radial to the radioulnar articulation

Contains the extensor digitorum communis and the independent extensor indicis

Compartment V:

Overlies the distal ends of the radioulnar joint on the dorsum of the wrist

Contains the extensor digiti minimi tendon

Compartment VI:

Contains the extensor carpi ulnaris tendon and lies between the apex of the ulnar styloid process and the ulnar head

In rheumatoid arthritis, this tendon may become displaced in an ulnar direction or may rupture.

Diagnosis

Signs and Symptoms

Symptoms can be referred to the wrist from the elbow, shoulder, and the cervical spine, and causes include the following:

Bisects the anterior aspect of the wrist; its distal end also is the anterior surface of the carpal tunnel.

To palpate the palmaris longus, have the patient flex the wrist and touch the tips of the thumb and small finger together in apposition; the palmaris longus becomes prominent along the midline of the anterior aspect of the wrist.

Carpal tunnel:

Lies deep to the palmaris longus and is defined proximally by the pisiform and the tubercle of the scaphoid and distally by the hook of the hamate and the tubercle of the trapezium

The transverse carpal ligament, part of the volar carpal ligament, runs between those bony prominences and forms a fibrous sheath containing the carpal tunnel anteriorly within a fibro-osseous tunnel.

Posteriorly, the carpal tunnel is bordered by the carpal bones.

The compartment transports the median nerve and the finger flexor tendons from the forearm to the hand.

Clinical significance:

Compression of the median nerve (CTS) can restrict motor function and sensation along the median nerve distribution of the hand.

Patients note discomfort over the wrist and numbness of the thumb and the index and middle fingers.

Patients often have paresthesias at night.

To support a diagnosis of CTS, reproduce:

Pain in the median nerve distribution by tapping over the volar carpal ligament (Tinel sign)

Symptoms by flexing the patient’s wrist to its maximal degrees and holding for at least 1 minute (Phalen test)

Flexor carpi radialis:

Flexor carpi radialis tendinitis can cause pain over the flexor aspect of the wrist.

On examination, pain is noted with palpation over the flexor carpi radialis tunnel (from 3 cm proximal to the wrist to the main insertion of the flexor carpi radialis on the base of the second metacarpal).

Examination also usually produces increased pain with resisted wrist flexion and resisted radial deviation of the wrist.

Vascular anatomy:

The radial artery can be palpated just radial to the flexor carpi radialis tendon.

The pulse of the ulnar artery may be palpated proximal to the pisiform bone just before it crosses the wrist on the anterior aspect of the ulna.

Most patients have both arteries, with the ulnar artery usually providing the dominant blood supply.

Scaphoid fractures may not be evident on initial radiographs and may be seen on repeat radiographs 7-10 days later.

Treatment

General Measures

Pregnancy Considerations

If the pregnant patient has symptoms of numbness and tingling in her fingers, the clinician should have a high index of suspicion for CTS (median neuropathy at the wrist).

An increased incidence of de Quervain tenosynovitis also occurs in new mothers. (The clinician should check for this condition by using the Finkelstein test.)

Miscellaneous

FAQ

Q: How can you differentiate between de Quervain tenosynovitis and thumb CMC arthritis on examination?

A: In de Quervain tenosynovitis, the patient is tender to palpation over the 1st dorsal compartment tendons over the radial styloid versus tenderness over the CMC joint in CMC arthritis. In de Quervain tenosynovitis, the patient has pain with ulnar deviation of the wrist with the thumb tucked into a fist, whereas with CMC arthritis, the patient has a positive grind test.

Q: What is the anatomic landmark for the scaphoid?

A: The â€œanatomic snuffbox is a small depression just distal and dorsal to the radial styloid process. It is easy to visualize when the patient extends the thumb laterally away from the fingers. Tenderness to palpation in this area after trauma suggests possible scaphoid fracture.